From 782b20762121d2a8070df71213da4676dcfad081 Mon Sep 17 00:00:00 2001
From: Max Semenik <maxsem.wiki@gmail.com>
Date: Mon, 16 Oct 2017 23:53:50 -0700
Subject: [PATCH] Switch DifferenceEngine to the new shell framework

Change-Id: Iad8718e5f54ed829efded8efbb0f3496c119e6ad
---
 includes/diff/DifferenceEngine.php | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/includes/diff/DifferenceEngine.php b/includes/diff/DifferenceEngine.php
index a9d6ad69d4..899054d6c4 100644
--- a/includes/diff/DifferenceEngine.php
+++ b/includes/diff/DifferenceEngine.php
@@ -21,6 +21,7 @@
  * @ingroup DifferenceEngine
  */
 use MediaWiki\MediaWikiServices;
+use MediaWiki\Shell\Shell;
 
 /** @deprecated use class constant instead */
 define( 'MW_DIFF_VERSION', '1.11a' );
@@ -966,8 +967,16 @@ class DifferenceEngine extends ContextSource {
 			fwrite( $tempFile2, $ntext );
 			fclose( $tempFile1 );
 			fclose( $tempFile2 );
-			$cmd = wfEscapeShellArg( $wgExternalDiffEngine, $tempName1, $tempName2 );
-			$difftext = wfShellExec( $cmd );
+			$cmd = [ $wgExternalDiffEngine, $tempName1, $tempName2 ];
+			$result = Shell::command( $cmd )
+				->execute();
+			$exitCode = $result->getExitCode();
+			if ( $exitCode !== 0 ) {
+				throw new Exception( "External diff command returned code {$exitCode}. Stderr: "
+					. wfEscapeWikiText( $result->getStderr() )
+				);
+			}
+			$difftext = $result->getStdout();
 			$difftext .= $this->debug( "external $wgExternalDiffEngine" );
 			unlink( $tempName1 );
 			unlink( $tempName2 );
-- 
2.20.1